The CH2M team also guided the city through a $32m upgrade that added a membrane bioreactor to the treatment system.

CH2M will see the city through the membrane replacement process over the next four years.

City manager Marty Colburn said: "CH2M has provided long-standing quality services. We are in the midst of a significant replacement process of the filtering process, and CH2M has the experience and know-how to implement it," said.

Originally built in 1932, the 8.5-million-gallon-per-day facility has been upgraded several times, and currently features advanced membrane filtration technology to produce high-quality treated effluent that helps sustain public and environmental health.